1. Field of the Invention
The present invention relates generally to plumbers' tools of the type employing a helically wound coiled spring or "snake" which is rotated and inserted into waste lines to remove blockages. More particularly, the invention concerns an improved device for pressurally gripping the coiled spring to cause its rotation as the casing containing the spring is rotated by an electric motor.
2. Discussion of the Prior Art
One of the most successful motor driven prior art portable plumbing tools ever developed is the tool described in U.S. Pat. No. 3,449,782. An improvement upon this device is described and claimed in U.S. Pat. No. 4,361,924 issued to the present inventor. The invention described herein is an improvement on the device of U.S. Pat. No. 4,361,924.
The tool of the present invention comprises a hand-held motor, a coiled spring, a storage housing for housing the coiled spring, and a manually operated chuck means through which the spring passes.
Several variations of devices of the general type herein described have been suggested. A great many of these prior art devices are difficult to operate principally because of a faulty design of the actuating means by which the chuck is moved into and out of gripping engagement with the spring. Unless this actuating means is properly designed, the operator cannot satisfactorily regulate the pressure being applied to the spring to controllably cause its rotation as the storage housing is rotated. If too much pressure is applied to the spring, the motor will become overloaded and the tool will fail to function properly creating a possibly dangerous situation. If too little pressure is applied to the spring, slippage will result and the spring will not rotate.
While devices of the previously mentioned patents were far superior to any devices in competition therewith, the actuating means of these devices did not enable the effortless and smooth actuation of the chuck assembly that is possible with novel construction of the present invention. More particularly, the device of the present invention overcomes the drawbacks of the prior art predecessor devices by providing a unique actuating means which permits positive actuation of the chuck using the heel of the hand rather than the fingers thereby increasing ease of operation as well as positive controllability of the tool.